.AddGuest{
    position: fixed;
    bottom:0;
    left:0;
    width:100%;
    z-index:100;
    text-align: center;
    height:40px;
    line-height:40px;
}

.AddGuest a{
    display: block;
    background:blue;
    color:#fff;
    font-size:20px;
}